用均匀设计优化食品中碘的碱灰化-砷铈催化分光光度法测定条件

目的 采用均匀设计法优化食品中碘的碱灰化-砷铈催化分光光度法的最佳测定条件.方法 根据现行食品中碘的碱灰化测定法,用均匀设计U*8(84)表安排实验条件(碳酸钾和硫酸锌混合液、氯酸钾和氯化钠混合液、灰化温度、灰化时间),测定大豆中的碘含量,并计算回收率,建立回收率和各测定条件的数学模型,计算测定条件的最优组合,最后使用该组合平行3次测定大豆中的碘含量,进行验证.结果 测定条件的最优组合为:碳酸钾和硫酸锌混合液1.5 ml,氯酸钾和氯化钠混合液1.5 ml,灰化温度550℃,灰化时间4.5 h.3次大豆碘含量测定的平均回收率为101.6％.结论 均匀设计法找到的最优测定条件的组合应用于食品(大豆)中碘的测定,结果满意.     

微波消解ICP/MS法测定人发硒含量研究

目的研究应用微波消解ICP/MS法测定人发中硒的含量。方法以硝酸-过氧化氢为消解酸体系通过微波消解人发样品,以ICP/MS测定含量。结果实验表明应用本方法检测人发中硒的含量,方法准确可靠,检出限0.2μg/L,相对标准偏差2.04%。结论应用微波消解ICP/MS法测定人发中硒含量准确、快速、高效。     

开放式灰化—电极法测定人粪便中总氟含量

本文报道一种运用新型开放式灰化炉及氟离子选择性电极测定人粪便中总氟含量的方法。我们用1克 NaOH 作固定剂,300℃和650℃分段将10ml 经预处理的粪样灰化,每一段加入0.25克 KNO_3以帮助灰化,灰样用盐酸(1∶1,V/V)溶解,调节 pH 并加入4ml TISAB 缓冲液,稀释到25ml 后用一次添加法测定结果。本法在2.0—100μg 范围内对标准氟(NaF)的平均回收率为95.0±5.6%;样品平均回收率为106.4±11.0%;两份样的变异系数分别为8.4%和9.4%;82次测定的空白值为1.62±0.41μg。     

恒温消解-流动注射氢化物原子吸收法测定血清中硒

目的 建立快捷、易行、准确的血清硒测定方法。方法 利用氯酸在130℃恒温下消化样品，以流动注射氢化物原子吸收法测定血清硒。结果 方法的线性范围为0～10μg／L，检出限为0．48μg／L，平均回收率为96．5％，合并变异系数为6．2％。结论 测定方法具有灵敏度高、重现性好、结果准确、操作简单、一次测定样品量大等优点，很适合硒缺乏病病区调查研究及临床硒相关疾病诊治的需要。     

氢化物原子荧光法测定食盐中硒含量方法探讨

目的探讨建立一种操作简便、灵敏度和准确度较高的盐硒测定方法。方法称取一定量盐样加水溶解,溶液中硒（Ⅳ）与硼氢化钠反应生成SeH2,然后用氩气载入电热石英炉中原子化,根据产生的荧光强度对溶液中硒进行定量检测。结果运用方法学评价试验得出氢化物原子荧光法测定食盐中的硒,线性范围（0.40~60.00）μg/L,检出限为0.40μg/L,RSD 1.05%,选高、中、低3种浓度的盐样做加标回收率96.81%~105.58%;而紫外分光光度法测硒盐的检出限为50μg/L,回收率92.10%~103.27%,两种方法差异无统计学意义（t〈t0.01,P〉0.01）。结论氢化物原子荧光法检出限低、重复性好、准确度高、操作简便、快速,适用于地方病实验室大批量的硒盐检测工作。     

食物中碘的碱灰化-砷铈催化分光光度测定方法的验证

目的 验证食物中碘的碱灰化-砷铈催化分光光度测定方法的精密度、灵敏度和准确度.方法 在样品中加入碳酸钾、硫酸锌、氯酸钾、氯化钠混合碱性助剂,于105℃下干燥3 h,电炉炭化约0.5 h,置于马弗炉中600℃灰化4 h,用水溶解灰粉后取上清液,砷铈催化分光光度法测定含碘量,并进行标准曲线线性范围及线性关系、灵敏度实验:选择3种含碘量不同的南瓜采用碱灰化后,分别做精密度和加标回收率实验;同时测定美国标准物(碘)和尿碘国家标准物,比较测定偏差.结果 采用碱灰化-砷铈催化分光光度测定,碘检测范围为4.4～250.0 ng;标准曲线的相关系数为-0.9997～-0.9993;当样品含碘量为45.8、145.0、195.6μg/kg时,变异系数(CV)分别为4.3%、3.0%、3.9%;低[(47.2±2.6)μg/kg]、中[(71.9±3.3)μg/kg]、高[(95.9±2.4)μg/kg]3种不同含碘量样品加标回收率分别为96.8%、97.8%、97.6%;对美国标准物测定,相对偏差为-6.5%;对国家尿碘(低、中、高)标准物测定,相对偏差分别为11.0%、10.7%和10.7%.结论 食物中碘的碱灰化-砷铈催化分光光度测定方法适宜于食品中总碘的测定,也适宜于尿中总碘的测定.     

微波消解-电热消解仪法和电热板加热消解法测定头发中的硒

目的进行发硒检测时,对头发前处理用微波消解-电热消解仪法和电热板加热消解法的比较。方法采用微波消解-电热消解仪法和电热板加热消解法两种方法对头发进行前处理,分别测定其硒含量。结果微波消解-电热消解仪法的相对标准偏差为1.65%,加标回收率平均值为96.2%;电热板加热消解法的相对标准偏差为2.69%,加标回收率平均值为92.8%。结论微波消解-电热消解仪法比电热板加热消解法具有操作简单、消解能力强、耗时短、回收完全、测定更加准确等优点,其可以优化头发样品分析的前处理。     

二氨基萘分光光度法测定盐硒

目的　建立适合于硒碘（Ｎａ２ＳｅＯ３－ＫＩＯ３）盐中硒的常规监测的分光光度法。方法　研究Ｓｅ４＋ 与二氨基萘反应的吸收光谱特性,干扰物质的干扰情况,对测定波长、试剂用量、反应时间、测定范围等进行了优化选择。结果　方法最低检出限为０．０２μｇ,摩尔吸光系数ε３６５ 为１．８×１０４,对不同硒含量的盐样中硒的测定,批内变异小于６．２％ ,批间变异小于９．７％ ,准确度范围为９７．９％～１０５．６％ ,该方法与其它法测定结果无显著性差异（ Ｐ＞ ０．２ ）。结论　该方法具有简便、经济、灵敏、准确等优点,适合于硒碘（Ｎａ２ＳｅＯ３－ＫＩＯ３）盐中硒的常规监测工作。     

HIV TP同步金标法快速检测结果的比较分析

目的为了对目标人群及临床疑似病人进行艾滋病毒(HIV)、梅毒螺旋体(TP)血清快速筛查诊断,并确保HIV、TP快速诊断试剂血清学的检测效果。方法采用Bioline同步HIV、TP胶体金快速检测试剂对浦东新区6个社区的≥60岁的老年人血清共10 000份进行TP、HIV血清学筛查,TP检测阳性者再用梅毒螺旋体明胶颗粒凝集试验(TPPA)试剂进行验证,阴性者随机抽取1 000例;HIV快速检测阳性者用Determine胶体硒免疫层析试剂进行比对,阴性者随机抽取1 000例分别TPPA试剂进行验证、用Determine胶体硒免疫层析试剂进行比对;另抽取2016-2019年确证实验室HIV筛查阳性待确证样本同时Determine胶体硒免疫层析方法阳性并蛋白印迹试验(WB)确证为阳性样本1 000例,对Bioline同步快速检测试剂进行验证。结果 1)Bioline同步HIV、TP金标快速诊断法相对于TPPA法的敏感性为98.94%,特异性为100%,其检测结果与TPPA一样包含了既往和现症感染;2)Bioline同步HIV、TP同步金标快速诊断法相对于WB确证实验敏感性100%,特异性99.84%,与Determine胶体硒快速法相比较(两种快诊试剂均以WB为"金标准"),差异均无统计学意义(P 0.01)。结论 Bioline同步HIV、TP金标快速诊断法可以取代Determine胶体硒免疫层析快速诊断用于门诊基层等医疗机构及个人自测,同时可以取代TPPA法用于梅毒筛查。     

温和酸消化砷铈催化反应测定尿碘应注意的问题

温和酸消化砷铈催化反应测定尿碘应注意的问题李惠萍张威温和酸消化砷铈催化反应测定尿碘是我国标准化了的尿碘测定方法。该方法较传统的碱灰化法，酸消化法具有操作简便、灵敏度高、重现性好、结果准确等优点。然而我们在实际工作中发现一些影响测定结果的因素，值得引起...     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.